Improvement in electro-magnetic fire-alarms



H. VAN ANSDALL. MAGNETIC DETECTOR OF FIRE AND BURGLARS.

N0.9.240. Patented Aug. 31, 1852.

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ATENT OFFICE.

HY. VAN ANSDALL, OF EATON, OHIO.

IMPROVEMENT IN ELECTRO-MAGNETl'C FIRE-ALARMS.

Specification forming part of Letters Patent No. 9,!40, dated August 31, 1852.

To all whom it may concern:

Be it known that I, HENRY VAN ANsDALL, of Eaton, in the county of Preble and State of Ohio, have invented a new and useful machine to give notice of the action of tire or burglars when doing any injury; and I do hereby declare that the following is a full and exact description.

The nature of my invention consists in providin g an alarm by a combination of two electro-circuits, one of which is to be broken by the action of tire or encroachment of burglars, together with a wheel driven by clock-work operating on a key of the other circuit.

To enable others skilled in the. art to make and use my invention, I will proceed to describe its construction and operation.

I take a box of suificient capacity to contain the apparatus, as A B 0 D in the drawings annexed, in which E F G H represent the lid of the box attached thereto by hinges. This lid also represents a door, sash, or windowshutter.

The apparatus consists of a foundation made fast to the back or bottom of the box, as a a.

b b is a block made fast to the side of the box for the support of the terminal point 3 M and M are electromagnets wrapped with insulated wire.

1st pt., 2d pt., and 3d pt. are posts for the support of other parts of the apparatus.

1 Z is an arm attached to the top of the post 2d pt., bent, and the downward point resting on the spring at m attached to the top of the post 1st pt., to which spring is riveted the armaturef f over the magnet M.

s s is a small spiral spring.

y g is a metallic key, playing on a pivot on the post 3d pt. On the under side of this key is the armature e 0 over the magnet M.

0 0 is a metallic bracket.

k k is a hook to catch in the notch 2' of the signal-wheel W W.

a n and 0 0 are'conducting-wires, n n being broken, lapped, and bound with some combustible material, as shown at w 20.

To use the apparatus, charge a galvanic battery and attach the opposite ends of the wire n n, as shown on the left of the drawings, to opposite poles of the battery, then let the lid of the box, door, sash, or window-shutter be closed; then the pointy will be in contact with the metallic plate P P at 1, and all will be quiet; but as soon as the points y and l are are detached (by the opening of a door, sash, or window-shutter b burglars, or the wire a a burned off at w w) e attractive power of the magnet M is lost. Then the spiral spring 8 8 draws down that end of the key until it strikes the bracket 0 c, which completes the magnetic circuiton the wire 0 0 thus From the positive pole of the battery 19 0, along the wire it n to the connection v v, thence on the wire 0 0 to the spring m, through the spring to the arm I l, on the arm to the wire 0 0, through the Wire to the key g 9, through the key to the bracket 0 0, through the bracket to the wire 0 0, wrapping the magnet M and charging it, thence to the connection 2 z, and from thence to the battery at N. The first circuit being thus broken, and the second closed, the attraction of the magnet M draws down the armature f f and spring on m. The circuit 0 0 is then broken by the spring m m leaving the downward point of the arm I l, destroying the power of attraction in M. The elastic force of the spring then raises itself until it again strikes the point of the arm I, which closes the circuit again, and thus alternately, which alternate breaking and closing produces a rapid vibration of the spring m m and armature f f, and gives the alarm by the sound produced; and, again, the closing of the second circuit by the key g'raises the hook kit, by pressing onits upper arm, out of the notch z', which sets the wheel \V at liberty. It then revolves, (by clock-work not shown,) and by manipulating the key 9 g gives a preconcerted signal at the magnet M thus: The wheel W, in revolving, breaks the circuit 0 o by raising the key 9 from the bracket cby the points, as at 2 2, adjusted on the Wheel W, coming in contact with the key 00,- but as soon as a point has passed the springs draws down the key 9 and closes the circuit 0 again. When the circuit 0 is thus closed the vibrations, before described, of the spring on m and armature f take place, but cease when broken by the points 2 on the wheel W coming in contact with the key 9, as described. Thus, by the arrangement of the points 2 2 on the wheel W at a greater or less distance, or for a time continuous, a definite signal may be given at cuit by breaking, lapping, and'binding with a combustible material or equivalent, for the purpose of making it sensitive to fire, as herein dedescribed.

HENRY VAN ANSDALL.

Witnesses:

J OHN W. ACTON, E. B. BOLENs. 

